thnik again!

When you believe you have seen every algorithm that exists for multiplying big numbers this video comes along and you are forced to think again.

KenKen™ is a mathematical and logical puzzle loosely similar to sudoku. It was invented by a Japanese mathematics teacher Tetsuya Miyamoto, innovator of the theory “The Art Of Teaching Without Teaching”, as an ‘instruction-free’ method of training the brain.

The objective is to fill the grid in with the digits 1 through 4 such that:

• Each row contains exactly one of each digit
• Each column contains exactly one of each digit
• Each bold-outlined group of cells contains digits which achieve the specified result using the specified mathematical operation: addition (+), subtraction (-), multiplication (x), and division (÷). – Wikipedia

The problem above is taken from an article in Times Online explaining how to solve simple KenKen. Enjoy!

Henry Dudeney claims the sum is correct. Do you agree?

It is inexcusable for scientists to torture animals; let them make their experiments on journalists and politicians. - Henrik Ibsen

One third of twelve, if you divide,
By just one fifth of seven,
The true result (it has been tried,)
Exactly is eleven.

From John Jackson, Rational Amusements for Winter Evenings, 1821, via Futility Closet.

You can tell a lot about a fellow’s character by his way of eating jellybeans. – Ronald Reagan

Almost 200 years ago John Jackson wrote ‘Rational Amusements for Winter Evenings.’ Here is one of his amusements.

If from six ye take nine, and from nine ye take ten
(Ye youths, now the mystery explain;)
And if fifty from forty be taken, there then,
Shall just half a dozen remain.

If you find the solution you no doubt will be amused, but if you don’t you may actually dislike the solution.

We are alone, absolutely alone on this chance planet: and, amid all the forms of life that surround us, not one, excepting the dog, has made an alliance with us. – Maurice Maeterlinck

- Drop what you are doing and listen to this!
- I am listening, but refuse to drop.
- Give me a number.
- 5.
- No, a much bigger number.

- 4.

- Very funny!
- I am glad you like it.
- Give me a number with ten digits.
- 9308376453.
- How many even digits does it have?
- Four. I guess 0 is even?
- You guessed right. And how many are odd?
- Six.
- 4610.
- A neat number. Is it the license plate of your car?
- You said 4 even, 6 odds, and 10 digits. That’s how I got the number.
- I forgot, you don’t even like cars!
- Repeat the process with 4610.
- OK. 4610 gives 314. The famous pi! I am excited!
- Forget pi for a minute, just continue the process.
- 314 gives 123.
- Continue.
- 123 gives 123. That is neat! End of story. The end of the Universe. By the way do you remember the number at the end of the Galaxy?
- Try another ten digit number.
- And do the same process?
- Exactly.
- But why?
- You may discover something interesting.
- Really?
- You never know.

Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for – in order to get to the job you need to pay for the clothes and the car, and the house you leave vacant all day so you can afford to live in it. – Ellen Goodman